The basic principle of employing a barge for mounting a cylinder rotating about a horizontal axis, which cylinder bears pivotable elements defining scoops or buckets and which acts to pick up dredge material beneath the water surface and then causing as the dredge material on the scoops moves out of the water to fall onto an inclined ramp which, in turn, acts as a chute to guide the dredge material to an accumulatin means, is found within U.S. Pat. No. 10,668 to Lyons issuing Mar. 21, 1854.
Further, the utilization of eccentric means for such buckets or scoops to cause them to project at one point during the rotation of a drum or cylinder, so as to effect scooping of the dredge from the floor of the sea bed underlying the barge and then to retract inwardly of the cylinder or drum as the buckets rotate on the drum to another point where the dredge is discharged, is exemplified by U.S. Pat. No. 1,196,426 to Bowling.
However, while such techniques have been employed in dredging machines over the past century, the apparatuses have not been very effective in operation. The scoops do not always automatically move freely into and out of the drum periphery to achieve the initial collection of dredge from the sea bed and the transfer of that dredge material from the drum periphery to a removal chute, ramp or the like in an adequate and efficient manner. Further, such machines have been complicated in structure and have been unable to adequately adjust to the varying dredge conditions, terms of compactness or density of the material being dredged or the depth to which dredging must occur.
It is, therefore, a primary object of the present invention to provide an improved dredging machine of this type which obviates the problems outlined above and in which the mechanism is simple in construction, wherein the submergence of the dredging drum may be readily varied and wherein the apparatus is equally capable of being borne by the barge at an intermediate barge position or at a forward end of the same.